Filter-press bag



J. P. HAMILTON FILTER PRESS BAG 2 Sheets-Shet 1 Filed April 4. 1923 avwentoz Nov. 23 1926.

1 000 O 0000 U o ou I o 0 .m o we 0 o llll Patented Nov. 23, 1926.

Jlhll'l'Ei STATES r al"? FEQE.

J'DHN R HAMILTON, 0F MILW'AUKEE, WISCONSIN, BY MESNE ASSIGN- MENTS, T0 ALLIS-CHALMERS MANUFACTURING CGF'PANY, OF MILWAUKEE, WIS- CONSIN, A CGRlORAT'EON OF DELAW'ARE.

FILTER-PRESS BAG.

Application filed April 4, 1923. Serial No. 529,810.

The present invention relates to improvements in metallic filter press bags and particularly to bags for use in a press of the general type shown in U. S. Patent 1,836,341, granted April 6, 1920 to John J. Berrigan.

The general purpose of the invention is to provide a metallic filter press bag of such construction that a plurality of them can be used in a press without separators or racks letween them, or at most with only a plain sheetof metal as a separator, the construction being such that there will be no inccessiblo or diliicultly accessible spaces to receive id retain sediment or dirt of any kind. \With a press bag mate in accordance with this invention, all parts may be cleaned readily so as to keep the apparatus in sanitary condition, while at the same time the press pressure is readily transmitted from the wall oi one bag to the adjacent wall of the adjacent bag and properly distributed to the contents of the bag, thus,

giving a durable bag.

As presses of the type described and with collapsible metallic bags are coming into general use for filter-pressing organic materials or a putrescible nature, it'becomes impor tant in many cases to have the press and bags in a thoroughly sanitary condition at all times during the operation. This is diil icult and even impossible to accomplish it"there are any inaccessible or ditficultly accessible pockets or spaces into which germs may enter and remain. lVith thepresent invention a structure is provided in which there are no such pockets or spaces and therefore the danger of contaminating the material being treated is materially reduced.

Atlfurther object of the invention is to pro-v vide a simple and durable press bag.

With these general objects in view, the

7 construction and combination of parts which will first be described in connection with the accompanying drawings and then" more away, oi a bag embodying the invention;

Fig. 2 an end view of the same;

Fig. 3 an enlarged sectional view, partly broken away, the section being taken on the line 3- 8, Fig. l; i

Fig l a horizontal section on the line 4%, F i2. 1;

F 5 a detail sectional View, illustrating the locking mechanism;

6 a detail view of one corner of a sig. 7 a detail view showing two bags ad- 3azent to each other in place in a press;

' 8 illustrates the general type of press with. which the bags are intended to be us" 9 is detail view showing a modified form of the invention; and

10 illustrates a separator between two bags.

deferring to the era-wings, A A are the side 'ies oi? the bag. Each side frame es top and bottom rails 1 and 2 re- V and stiles 8, made of heavy sheet l. While these frames may be stamped ,of one sheet of metal or the desired thickness, it is generally more economical to use strips of metal of the requisite widths and then weld these strips together to form the frame. In practice the stiles are buttweldedto the rails by electric or oXy-acetyl-eiie welding. In the embodiment of the invention shown, the stiles are considerably wider than the rails. 1 For the purpose of suitably hanging the filter has; i he press, tl e top rails l are extended be L the stiles and bottom rails, as shown in A 1, each overhanging end oi the top rail being provided with a slot, as indicated at l, and also with a block 5, riveted to the top rail and having a down ward-extending portion arranged to engage the inner face of the main supporting rail 6 of the press.

To each frame is secured a panel plate B of suitable metallic toraminous material.

In the best embodiment of the invention,

pane-hplate of such dimensions that its edges will be substantially flush with the edges or Hit) the frame. In the embodiment of the invention illustrated in Figs. 1 to 7, the panelplate is secured to the outer face of its respective frame. In the construction shown in Fig. 9, the panel plate is secured to the inner face of its frame.

On the outer face of each bag-wall there is arranged a plurality of pressure-transmitting bars, indicated at C. In the best embodiment of the invention, these bars are rectangular in cross-section and are arranged vertically, each bar having one of its narrow faces in contact with the panelplate. The bars C have a length somewhat less thanthe height of the frame, but sufficient to allow them to be riveted to the top and bottom rails. These bars are spaced apart sufiiciently to allow a proper discharge of liquid from the material in the bag, while at the same time, the bars must be close enough to properly sustain the perforated metal so that it will not sag too much be tween the bars, when subjected to the pressure of the materials which are being pressed.

In the construction shown in Figs. 3 and a, each bar has the same width or depth throughout its length. In the construction shown in Fig. 9, each bar is notched into the frame so its inner face may touch the panelplate and support it.

The sde walls of the bag, formed by the two frames and their panel plates, are connected at the sides by collapsible end members. In the best embodiment of the invention, each end member comprises two leaves, D, D hinged together along their meeting edges, and also hinged to fixed leaves d, d, respectively, secured to the; correspondmg frame, as shown in Fig. 4.

Each of the fixed leaves, 03 and al is secured to the frame by rivets which pass through the. leaf, through the corresponding stile, and through the corresponding panel-plate, some of the rivets also passing through the (oi-responding vertical pressure bar at that end of the bag.

the center to form an inverted V or gable, as will be clear from Fig. 3.

The bag is provided with a collapsible top, which comprises leaves E and E hinged to fixed leaves 6 and e secured to the respective top rails of the corresponding frames, and locking means for holding the two leaves together. In the present instance the loking means comprises a suitable loeking strip 6 which is advantageously an angle-iron strip having one flange turned outward and the other riveted to its leaf. This locking strip is arranged to be engaged by a series of hooks e fixed on a rotatable red a journaled in bearings e riveted to the downward-turned flange of an angle- Each collapsibleend member also has the upper end of its two leaves sloped in opposite directions from iron strip 6 having its other flange hinged to the leaf E The rod 0* has its ends extended beyond the back and cranked to form handles by which the rod may be rotated by the operator, as shown in Fig. l. The hooks may be turned so that their ends project through slots cut in the angle-iron strip 6 and bear against the edge of the vertical flange of the locking strip 0 as shown in Fig. This will lock the bag against the internal pressure of the materials.

The rivets which hold the fixed leaves d, d to the crn'responding frames pass through the corresponding top rails and through the corresponding panel plates.

The inside of the bag near the bottom is provided with suitable sealing means, as, for example, the two sealing bars F, Fig. 3, one for each side of the bag. These bars are riveted to the respective lower rails, the rivets passing through the panel plates. It is advisable to bevel or chamfer these bars on their upper surfaces so that the press cake may easily be discharged from the bag.

When a collapsible bag of the type described is used in a press of the type disclosed in Patent 1,336,3il, as shown in Fig. 8, the bottom of the bag is collapsed to close it, while the top is still open, so that the side members of the bag slope toward each other from the top to the bottom. In order to permit this to be done without injury to the end members D, D the latter have leaves of such width that the metal of the leaves may be twisted or distorted, due to the variation in the opening of the different parts of the bag, without exceeding the elastic limits of the metal. In practice the desired result above mentioned will be insured by making the width of each leaf of an end member greater than the widest opening of the bag.

In operation, a plurality of bags are used. The outer faces of the pressure-transmitting bars C of one side wall of a bag register or contact with the faces of the bars C on the adjacent wall of the adjacent bag. WVhen the bags are filled with material to be pressed and their top closures locked, the pressing operation may begin. The liquid expressed from the bag through the openings in the side wall will flow down readily through the discharge channels formed by the spaces between the bars C. As the press squeezes the bags, there is a tendency to a slight shifting of the bags with relation to each other, usually in a vertical plane. This may cause a slight wear of the bags against each other, but this wear is confined to the outer faces of the pressure-transmitting bars C of each frame, and does not in any way affect the platen-plates B of the bags. Hence, for this reason the bags are more durable than would be the case where separators or racks were employed which contacted directly with the panel-plates. It is obvious that the bags may be cleaned readily, there being free access to the drainage channels between the bars when the bags are separated.

The locking device for the top closure will be found very efiicient in resisting the internal pressure of the material in the bag, and yet maybe readily released when the bag is to be opened. On account of the hinge-joint between the locking member and the leaf E to which it is attached, the topclosure approximately fits the gable or pointed ends of the end-members at all conditions of the bag, thereby preventing the escape of material over the ends of the bag as the press closes.

If desired, a separator may be inserted between the bags, but in this case the separator can be merely a fiat sheet of metal as indicated at f, Fig. 10, having lugs f at the top which serves to prevent the sheet from dropping to the floor when the press is opened. As soon as the press closes the separator is held by the pressure of the bags against it. Such a separator may readily be removed and cleaned as it does not have any inaccessible pockets to trap the dirt.

l. The filling, pressing and emptying of the bags takes place in the usual way in presses of this type.

It will be observed that in the construction hereinbefore described, the metallic filter press bag is provided with a separator device on each side, these separator devices being a permanent part of the bag. Fun thermore, these separator devices are 01 such construction as to form open channels, readily accessible for cleaning when the bag is out of the press. The pressuretransmitting members, or bars, which produce the channels between each pair of such members not only serve to take the wear due to the sliding of one bag relative to the other, as hereinbefore described, but also serve to stiffen the bag frame to which they are riveted.

What is claimed is:

A filter-press bag unit comprising interconnected foraminous metallic side walls each. having a plurality of pressure-transmitting bars permanently attached to the unit at the wall edges and spaced apart to provide external outwardly open drainage channels directly upon the unit, said bars being formed for coaction with similar bars of an adjacent unit to prevent outward distortion of said walls at said bars and to form unobstructed open ended conduits extending entirely across the adjacent sides of the cooperating units.

In testimony whereof, I have hereunto set my hand.

JOHN P. HAMILTON. 

